Beverage containers having self contained straws have been known for years including those which incorporate tab tops, but even with growing environmental concerns, none of them have been successful in being widely adopted. The advantages of a completely self contained drinking unit are evident. Not only does such a unit provide a sanitary means of access to the beverage but avoids the waste of paper covering used to enclose sanitized straws. Drawbacks of prior devices relate to their inability to be aligned with the opening of the container without expensive mechanisms, complicated installation and/or inordinate manufacturing costs.
Larson et al U.S. Pat. No. 4,877,148 discloses mechanisms for incorporating a pop--up straw into various types of containers such as beverage cans and bottles. In each case, the top of the straw is retained by a lip adjacent the container opening so that projecting the straw from the container requires some means of reacting with a pushed in surface to free the straw from the lip. A coiled spring of plastic line is disclosed in FIG. 9 of Larson et al that acts in conjunction with accordion pleats. Not only does this require a pleating operation on the straw itself, but exposes one to the danger of a loose coil spring floating in the beverage.
Cornelius U.S. Pat. No. 3,349,955 discloses a beverage container with a pop-up straw which requires a specially constructed tubular member on the bottom side of a lipped can; this presents expenses not only in converting a simple can structure to a complex structure, but also requires one to accurately align the top of the straw with the tubular member.
Gilliem U.S. Pat. No. 3,547,308 discloses various means for popping a straw out of a can including a spring-biased bellows, a float and a coil spring. The coil spring is mounted within the bellows itself or externally to the straw. In any event, a mechanism of substantial complexity is required, necessitating extensive modification of the normal structure of the beverage can.
Mack et al U.S. Pat. No. 4,228,913, discloses a beverage can including a straw with a bellows section which automatically raises the straw. A separate and complex straw retainer and guide is required to be affixed internally of the can.
Johnson et al U.S. Pat. No. 4,709,829, discloses a pop-up straw for a beverage can in which the straw not only has pleats but is also fitted with a float and must be preset into an orifice structure serving to center the straw.
Pugh U.S. Pat. No. 3,295,715; Park et al U.S. Pat. No. 4,582,213; and Ayabe et al U.S. Pat. No. 4,712,702, each disclose complex opening mechanisms in which a straw is attached to the pull tab of a container.
Sequeira U.S. Pat. No. 3,226,001, discloses a modification to a can or bottle closure which includes a slot or aperture sized to retain the straw so that when the tab or bottle cap is removed, the straw must be grasped by the fingers to be withdrawn.
All the above containers include some mechanism for securing the straw in a particular position within the container, many of which involve fairly complex and expensive structures. The present invention provides a simple, inexpensive mechanism that not only provides a pop-up capability to a straw assembly but automatically centers the straw so that assembly with the container is simple. A unique straw assembly is provided for use with containers that have a sloping upper surface. More specifically, a beverage container having a sloping upper wall is provided having an enclosed self contained pop-up straw assembly formed of telescopic tubes and resilient means urging the tubes apart against the sloping wall. The straw assembly tends to center itself in the container and pop up when the container is opened.
The container can be a bottle having a neck providing a sloping wall, or can be a carton with a gabled top. In a preferred embodiment, the container is a cylindrical can in which the sloping wall constitutes the top wall of the can. The slope defines an apex, preferably centrally on the can top, formed with tab cap closure disposed on the apex and movable, e.g., backwardly bendable, to expose the contents of the container. By reason of its spring construction, the straw centers itself to the apex so that when the tab cap is bent back, the straw is released and projects out of the opening, i.e., it pops up.
The straw assembly comprises telescoping inner and outer tubes with the bottom end of the inner tube being integrally formed with a coil that extends into the bottom end of the outer tube. The tubes have sufficient clearance to enable them to telescopically slide with respect to each other, but not so large as to impede the drawing of liquid up through the inner tube. A clearance of about 0.1-0.3 millimeter is generally sufficient to provide the desired results.
The present invention overcomes the disadvantages of prior art straw assemblies by providing a straw which is very simple in construction yet operates with simple surfaces of the container to center itself and project from the container when it is opened.